Motherhood may do little to slow Serena Williams’s pursuit of grand slam success but more hungry opponents, if they emerge, could yet deny her the all-time singles record, the women who holds that distinction told Reuters.

Australian great Margaret Court won 24 grand slam singles titles, one ahead of American Williams, who confirmed she was pregnant on Wednesday and will sit out the rest of the season.

Court, 74, who straddled the sport’s amateur and professional eras, was also the first mother to win a major as a professional. She took three of those titles in 1973, the year after giving birth to her first child Daniel.

But she rejoined the tour at 31 while Williams would be 36 if she came back as planned in 2018, a difference Court thought might play a role.

“Coming back after Daniel I had one of my best years …(but) I was quite a few years younger (than Serena),” Court told Reuters in an interview on Thursday.

“And I think you’ve got to know physically what you can do and how you can do it. You put the baby first and that to me was everything at the time. But we’re all different.”

The only other mothers to win slams in the Open era are Court’s compatriot Evonne Goolagong and Belgian Kim Clijsters who were both 26 when they came back.